Aircraft are pressurized to maintain an atmosphere suitable for the comfort and safety of occupants at all levels of flight. When a pressurized airplane is flying at a high altitude, the pressure outside the airplane is considerably lower than inside. Should a cargo compartment experience a sudden decompression while at a high altitude it would set up a sudden pressure differential between the passenger and cargo compartments. The floor of the passenger compartment could be designed to withstand the sudden pressure differential or means could be provided to suddenly equalize the pressure in the two compartments. It is known to use a series of lower sidewall blow out panels held in place with an off-center hinge that pivots to move the panel aside in response to a sudden pressure differential. In U.S. Pat. No. 3,012,572 to Bargetzi et al, a relief valve is mounted to a wall of an equipment housing located in an airplane to allow decompression of the housing if the cabin of the airplane is breached. It was found that a series of sidewall decompression units will allow communication between a passenger and cargo compartment under normal operating conditions while quickly opening to allow decompression in response to a sudden pressure differential.